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Help the chief engineer complete the warning label on the space station's new espresso machine.

The zero-gravity espresso machine will overheat and spray hot foam everywhere _____ you remember to engage the magnetic cup holder.

The correct answer is unless.

"Unless" means "if not" or "except if." The sentence means the machine will explode if you do not remember the cup holder. Using "if," "provided that," or "as long as" would hilariously imply that the machine explodes when you do everything right!

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Conditional Sentence

As is typical for many languages, full conditional sentences in English consist of a condition clause or protasis specifying a condition or hypothesis, and a consequence clause or apodosis specifying what follows from that condition. The condition clause is a dependent clause, most commonly headed by the conjunction if, while the consequence is contained in the main clause of the sentence. Either clause may appear first.

Different types of conditional sentences (depending largely on whether they refer to a past, present or future time frame) require the use of particular verb forms (tenses and moods) to express the condition and the consequence. In English language teaching the most common patterns are referred to as first conditional, second conditional and third conditional; there is also a zero conditional and mixed conditional.

Conjunction

In grammar, a conjunction is a part of speech that connects words, phrases, or clauses that are called the conjuncts of the conjoining construction. The term discourse marker is mostly used for conjunctions joining sentences. This definition may overlap with that of other parts of speech, so what constitutes a "conjunction" must be defined for each language. In English a given word may have several senses, being either a preposition or a conjunction depending on the syntax of the sentence (for example, "after" being a preposition in "he left after the fight" versus it being a conjunction in "he left after they fought"). In general, a conjunction is an invariable grammatical particle and it may or may not stand between the items conjoined.

The definition may also be extended to idiomatic phrases that behave as a unit with the same function, e.g. "as well as", "provided that".

A simple literary example of a conjunction: "the truth of nature, and the power of giving interest". (Samuel Taylor Coleridge's Biographia Literaria)

Conjunctions may be placed at the beginning of sentences: "But some superstition about the practice persists".

Examples

  • "But she must give security that she will not marry without royal consent, if she holds her lands of the Crown, or without the consent of whatever other lord she may hold them of."—Magna Carta (1215), translated into modern English
  • "But we, or our chief justice if we are not in England, are first to be informed."— Magna Carta (1215), translated into modern English
  • "And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor."
  • "But in all such Cases the Votes of both Houses shall be determined by Yeas and Nays, and the Names of the Persons voting for and against the Bill shall be entered on the Journal of each House respectively."—United States Constitution (1787)
  • "And the Congress may by general Laws prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof."—United States Constitution (1787)
  • "And this power has been exercised when the last act, required from the person possessing the power, has been performed."—United States Supreme Court Judgment (1803)
  • "But, in a larger sense, we can not dedicate, we can not consecrate, we can not hallow this ground." Abraham Lincoln's Gettysburg Address (1863)
  • "Yet, if God wills that it continue until all the wealth piled by the bondsman's two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said "the judgments of the Lord are true and righteous altogether."Abraham Lincoln's Second Inaugural Address (1865)
  • "So the inquiries can coexist, though there is much overlap between them."
  • "And it appears that it was this latter factor which underlay the dismissal of the appeal by the majority. But it seems to me that the question of whether it is fair, just and reasonable is better considered against the background of whether a sufficiently proximate relationship exists."
  • "But the earlier decisions in Pratap Narain Singh Deo and Valsala K. were not brought to the notice of the Court in the two later decisions in Mubasir Ahmed and Mohd. Nasir."
  • "And now we have Facebook and Twitter and Wordpress and Tumblr and all those other platforms that take our daily doings and transform them into media."
  • "So any modern editor who is not paranoid is a fool".
  • "And strikes are protected globally, existing in many of the countries with labour laws outside the Wagner Act model."

Negation

A finite indicative verb (or its clause) is negated by placing the word not after an auxiliary, modal or other "special" verb such as do, can or be. For example, the clause I go is negated with the appearance of the auxiliary do, as I do not go. When the affirmative already uses auxiliary verbs (I am going), no other auxiliary verbs are added to negate the clause (I am not going). (Until the period of early Modern English, negation was effected without additional auxiliary verbs: I go not.)

Most combinations of auxiliary verbs etc. with not have contracted forms: don't, can't, isn't, etc. (Also the uncontracted negated form of can is written as a single word cannot.) On inversion of subject and verb (such as in questions), the subject may be placed after a contracted negated form: Should he not pay? or Shouldn't he pay?

Other elements, such as noun phrases, adjectives, adverbs, infinitive and participial phrases, etc., can be negated by placing the word not before them: not the right answer, not interesting, not to enter, not noticing the train, etc.

When other negating words such as never, nobody, etc. appear in a sentence, the negating not is omitted (unlike its equivalents in many languages): I saw nothing or I didn't see anything, but not (except in non-standard speech) I didn't see nothing. Such negating words generally have corresponding negative polarity items (ever for never, anybody for nobody, etc.) which can appear in a negative context, but are not negative themselves (and can thus be used after a negation without giving rise to double negatives).

Humor

Humor is subjective, but at least the author tried.

B2 | Upper Intermediate

B2, or Upper Intermediate, is the fourth level on the CEFR scale. It marks the point where you move from "getting by" to genuinely comfortable communication — handling complex topics, expressing nuanced opinions, and understanding most of what you read or hear in real-world contexts.

What a B2 user can do

At this level, you're expected to:

  • Understand complex texts on both concrete and abstract topics, including technical discussions in your own field.
  • Follow extended speech and lectures, even when the structure isn't entirely clear, as long as the topic is reasonably familiar.
  • Interact fluently and spontaneously enough that conversations with native speakers flow naturally — without strain on either side.
  • Produce clear, detailed text on a wide range of subjects, using connectors and cohesive devices to build well-structured arguments.
  • Explain and defend a viewpoint on a topical issue, weighing the advantages and disadvantages of different options.
  • Recognize implicit meaning — reading between the lines in demanding, longer texts.

What B2 grammar looks like in practice

B2 is where grammar stops being about isolated rules and starts being about flexibility and precision. You're expected to control structures like:

  • Advanced conditionals and mixed conditionals — moving beyond simple if-clauses to express hypothetical and counterfactual meaning.
  • Passive voice in varied tenses and contexts, not just present and past simple.
  • Reported speech with correct sequence of tenses, including backshifting and reporting verbs.
  • Participle clauses and the distinction between participles and gerunds.
  • Comparative and superlative structures beyond basic -er/-est, including double comparatives and qualifying expressions.

Errors still happen at B2, but they rarely cause misunderstanding. The goal is controlled, flexible use of language across social, academic, and professional settings.

How B2 fits in the CEFR progression

B2 builds directly on the foundations of B1 (Intermediate) and prepares you for C1 (Advanced). Many university entrance exams, professional certifications, and immigration requirements target B2 as the minimum standard.

Self-check: If you can read a newspaper editorial, follow most of a TED talk without subtitles, and write a clear essay arguing a position — you're likely operating at B2.

Ready to test yourself? Try Is your English level B2/Upper Intermediate? or practise specific B2 grammar with challenges like Basics. Advanced Conditionals And "wish", Basics. Passive Voice, and Sequence of Tenses in Indirect Speech.

Difficulty: Medium

Medium difficulty. Difficulty levels represent author's opinion about how hard a question or challenge is.